The Flight Safety Foundation (FSF) estimates the apron-damage costs to the world's airlines to be $4 billion every year. For corporate fleets, the damage-related cost was estimated to be $1 billion annually.
The presented apron-damage costs include direct costs resulting from material and work related to an accident, and indirect costs resulting from aircraft being not in operation, harming the public image of airlines, incident investigations, etc.
Three main causes of surface accidents were indentified from the NTSB database: the failure to maintain adequate visual lookout, the failure to perceive distance between the wings and obstacles, and the failure to maintain required clearance.